diff options
Diffstat (limited to 'net/ipv4/ip_tunnel.c')
| -rw-r--r-- | net/ipv4/ip_tunnel.c | 99 |
1 files changed, 55 insertions, 44 deletions
diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c index 394cebc96d22..945734b2f209 100644 --- a/net/ipv4/ip_tunnel.c +++ b/net/ipv4/ip_tunnel.c @@ -472,6 +472,54 @@ drop: } EXPORT_SYMBOL_GPL(ip_tunnel_rcv); +static int tnl_update_pmtu(struct net_device *dev, struct sk_buff *skb, + struct rtable *rt, __be16 df) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + int pkt_size = skb->len - tunnel->hlen; + int mtu; + + if (df) + mtu = dst_mtu(&rt->dst) - dev->hard_header_len + - sizeof(struct iphdr) - tunnel->hlen; + else + mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu; + + if (skb_dst(skb)) + skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu); + + if (skb->protocol == htons(ETH_P_IP)) { + if (!skb_is_gso(skb) && + (df & htons(IP_DF)) && mtu < pkt_size) { + memset(IPCB(skb), 0, sizeof(*IPCB(skb))); + icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu)); + return -E2BIG; + } + } +#if IS_ENABLED(CONFIG_IPV6) + else if (skb->protocol == htons(ETH_P_IPV6)) { + struct rt6_info *rt6 = (struct rt6_info *)skb_dst(skb); + + if (rt6 && mtu < dst_mtu(skb_dst(skb)) && + mtu >= IPV6_MIN_MTU) { + if ((tunnel->parms.iph.daddr && + !ipv4_is_multicast(tunnel->parms.iph.daddr)) || + rt6->rt6i_dst.plen == 128) { + rt6->rt6i_flags |= RTF_MODIFIED; + dst_metric_set(skb_dst(skb), RTAX_MTU, mtu); + } + } + + if (!skb_is_gso(skb) && mtu >= IPV6_MIN_MTU && + mtu < pkt_size) { + icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); + return -E2BIG; + } + } +#endif + return 0; +} + void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, const struct iphdr *tnl_params, const u8 protocol) { @@ -483,7 +531,6 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, struct rtable *rt; /* Route to the other host */ unsigned int max_headroom; /* The extra header space needed */ __be32 dst; - int mtu; int err; inner_iph = (const struct iphdr *)skb_inner_network_header(skb); @@ -560,51 +607,11 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, dev->stats.collisions++; goto tx_error; } - df = tnl_params->frag_off; - if (df) - mtu = dst_mtu(&rt->dst) - dev->hard_header_len - - sizeof(struct iphdr); - else - mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu; - - if (skb_dst(skb)) - skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu); - - if (skb->protocol == htons(ETH_P_IP)) { - df |= (inner_iph->frag_off&htons(IP_DF)); - - if (!skb_is_gso(skb) && - (inner_iph->frag_off&htons(IP_DF)) && - mtu < ntohs(inner_iph->tot_len)) { - memset(IPCB(skb), 0, sizeof(*IPCB(skb))); - icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu)); - ip_rt_put(rt); - goto tx_error; - } - } -#if IS_ENABLED(CONFIG_IPV6) - else if (skb->protocol == htons(ETH_P_IPV6)) { - struct rt6_info *rt6 = (struct rt6_info *)skb_dst(skb); - - if (rt6 && mtu < dst_mtu(skb_dst(skb)) && - mtu >= IPV6_MIN_MTU) { - if ((tunnel->parms.iph.daddr && - !ipv4_is_multicast(tunnel->parms.iph.daddr)) || - rt6->rt6i_dst.plen == 128) { - rt6->rt6i_flags |= RTF_MODIFIED; - dst_metric_set(skb_dst(skb), RTAX_MTU, mtu); - } - } - - if (!skb_is_gso(skb) && mtu >= IPV6_MIN_MTU && - mtu < skb->len) { - icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); - ip_rt_put(rt); - goto tx_error; - } + if (tnl_update_pmtu(dev, skb, rt, tnl_params->frag_off)) { + ip_rt_put(rt); + goto tx_error; } -#endif if (tunnel->net != dev_net(dev)) skb_scrub_packet(skb); @@ -631,6 +638,10 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, ttl = ip4_dst_hoplimit(&rt->dst); } + df = tnl_params->frag_off; + if (skb->protocol == htons(ETH_P_IP)) + df |= (inner_iph->frag_off&htons(IP_DF)); + max_headroom = LL_RESERVED_SPACE(rt->dst.dev) + sizeof(struct iphdr) + rt->dst.header_len; if (max_headroom > dev->needed_headroom) { |
